Since the 1960s, many scientists have argued that the emergence of eukaryotes — cells containing a clearly defined nucleus — happened in response to the oxygenation of Earth’s surface environment. But new research led by Stanford University and University of Exeter scientists suggests eukaryotes in fact emerged in an anoxic environment in the ocean. Asgard archaeon. Scale bar – 500 nm. Image credit: Imachi et al., doi: 10.1038/s41586-019-1916-6. “We...
